iOS
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Swift 6
Kodebits Day 5: Closure Capturing
Apr 13 2026
Values are captured by reference in closures by default in Swift.
What is the output?
var i = 0
var ops: [() -> ()] = []
for _ in 1...3 {
ops.append { print(i) }
i += 1
}
ops[0]()
ops[1]()
ops[2]()
Try it in the online Swift Playground →
[spoiler title="Solution"]
Answer:
3 3 3
Explanation:
Closures capture variables by reference. The loop finishes with i=3. All closures print the current value of i, which is 3.
[/spoiler]